Since establishment the conventional technique relating to one-pass operation for color print performed with a color printer and a method for controlling heat pulse of a color printer, respective heat elements constituting a thermal head have been distinguished between coloring heat elements which are to perform color print at a printing medium and non-printing heat elements which are not to perform color print thereat. Incidentally, in a conventional printer disclosed in JP Laid-open patent application publication No. 2012-76351, at the time of performing color print with a thermal head, color development heat is applied to coloring heat elements of the thermal head while auxiliary heat (not so hot for color printing at a printing medium) is applied to either non-printing heat elements or coloring heat elements depending on print speed.
The above conventional printer is configured to perform black-and-white print on a thermo sensitive medium and perform color print on a printing medium by transferring color of a colored ink ribbon to the printing medium. That is, one-pass operation disclosed in the above-specified publication is applicable to a printer which is configured to perform one-colored print by using the thermal head. Accordingly, the print technique of the printer disclosed in the above publication is not applicable to a color printer which performs multicolor print on a color thermosensitive medium as printing medium in one-pass operation by using a thermal head as well as a method for controlling heat pulse of the color printer.
Further, in the color printer and the method for controlling heat pulse of the color printer, a pattern of color development heat to be applied to coloring heat elements of the thermal head is made different for each color to be printed at a color thermosensitive medium as printing medium at the time of performing multicolor print with the thermal head in one-pass operation. Therefore, it is not preferable to apply auxiliary heat to some of or all of the non-printing heat elements of the thermal head at constant pattern regardless of colors to be printed on a color thermosensitive medium at the time of performing multicolor print by using the thermal head in one-pass operation.